Minimig Video d/a resistor ladder

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Revision as of 17:04, 22 August 2007 by Freqmax (talk | contribs) (imported from 'Minimig Board v1.0 documentation' section)
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Equations:
Total resistance = 1/(1/4000+1/2000+1/1000+1/560)+75
Common current through resistor ladder plus vga impedance (75 ohm) = 3.3V / 357.8282..
Current * vga impedance = 0.6917V (specification says 0.7 p-p)
Output voltage = 75 * (3.3/(1/(1/4000+1/2000+1/1000+1/560)+75)) = 0.6917V
Simplification:
U = (75*3.3)/(1/(1/4000+1/2000+1/1000+1/560)+75) = 0.6917V
wikipedia: Resistor
wikipedia: Preferred number
digikey: Resistors